I have a carbed 2.8 . Toward the back of the manifold there is a vacuum line (Not for brakes). I was wondering if anyone knows were it is supposed to connect too?

 

IF I read this schematic of the hose set up right,
I'd say a sensor that goes to firewall.
Thin hard plastic line?
Goes behind the air cleaner?
Comes off carb?
Please don't ask to scan, I'm no good at scanning.
Wish I knew on Fri. Sat. I was at a place that does scanning.
I'd check a Chiltons at the parts store before ya buy, open to vacuum hose routing section.

 

I hooked the vacuum line up to that sensor and it gives me the check engine light. So i put the other vacuum line back on the sensor and all is fine again.

I read somewhere that maybe it goes to the choke pulloff ??

Any more suggestions?

 

The three lines off the BACK of carb go to
A "T" section, that also hooks to A. Cleaner & Air Management Valve, Middle hose goes to firewall sensor, last one must be thick & hooks to the "PCV".
One line on side, goes to the TBVS which hooks to purge canister.
The hose FROM A. cleaner goes to the vacuum secondary Break on carb, the one closest to firewall.

 

ok got the vacuum right. Does anyone know how to adjust the choke pulloff

 

Fast Idle Speed
With Throttle on High step of cam, adjust fast idle screw to obtain specified speed (of 2500).

SET IDLE SPEEDS IN Closed Loop Mode, engine idling, in gear, as wheels are choked & brake is on.

From sticker I've got.

Check vacuum operation of the pull off.
Mine are shot, I live with it for now.
I smog test in warmed up engine mode for my Blazer & it's usually warmer in SoCal.

 

I hope this can assist ya better.